Process for making electrically conducting polymers and polymers made by such process

ABSTRACT

A one-step process for synthesizing electrically conducting polymers of iodine doped poly N-alkylcarbazoles is disclosed together with the conducting polymers made by the process.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to electrically conducting organicpolymers and, more particularly, a one-step chemical method of makingcharge-transfer acceptor doped poly N-alkylcarbazoles together with theresulting new conducting polymeric organic semiconductors.

2. Description of the Prior Art

High molecular weight organic polymer materials are generallynon-conductive because they do not have free electrons like metals. Ithas been found, however, that certain high molecular weight materialshaving intrinsic double bond structures such as polyacetylene,polythiazine and polypyrrole may become highly conductive when dopedwith certain electron acceptors or donors. These compounds have provedto be of a great deal of interest inasmuch as they may combine some ofthe traditional properties of organic polymers such as high strength,light weight, flexibility and low temperature processing together withselective electrical properties including high electrical conductivity.In addition, their cost is relatively low.

Such materials undoubtedly will have an important impact on many areasof technology, especially the electronics industry. For example,experimental batteries made from conducting polymers have been shown toexceed current power sources in both power and energy densities. Otherareas of potential applications include chemical or gas sensors, lowcost, large area optical sensors, switches, light weight electricalconnections, wire, and in their film form for many types ofmicroelectronic circuits and large area solar cells.

Thus, organic materials that behave as metals or semiconductors willprovide the advantages of these materials together with additionaladvantages of being soluble in organic solvents or having low meltingpoints and glass transition temperatures which both minimize the cost ofprocessing and permit composites to be made with thermally sensitivematerials such as doped Si or GaAs, for example. The enormous moleculardesign flexibility of organic chemistry enables precise tailoring ofproperties to fill a wide range of applications as enumerated above. Inaddition, the high strength and conductivity-to-weight ratios lend theadvantage of fabrication of many electrical devices of much lower weightthan conventional materials.

In the prior art, a large number of polymeric conductors have been made.These include polyacetylene and its analogues which may be doped withI₂, AsF₅ and BF₄ ⁻ or the like. In addition, various phenylene polymersand phthalocyanine complexes have been synthesized as conductivematerials.

Highly conducting p-type materials have been obtained by doping thepolymer with a charged transfer acceptor such as I₂ or AsF₅ from the gasor with ClO₄ ⁻ or BF₄ ⁻ by electrochemical oxidation. An n-type materialhas been achieved by a doping with alkali metal. In known cases of thesetwo types of materials, however, to date only the p-type show anyenvironmental stability.

Theoretically, conductivity takes place both along the polymer chain andbetween adjacent chains. The active charge carrier, at least in thearomatic materials, is believed to be a bipolaron that is delocalizedover several monomer units. The mobility of such a species along thepolymer chain is reduced by conformational disorder, necessitating arigid highly crystalline chain structure for maximum intrachainconductivity. Various mechanisms such as "hopping" and "interchainexchange" are thought to be responsible for the interchain part of theconductivity. Unfortunately all of the most highly crystalline polymersof high conductivity are insoluble and infusable. Such is the case withthe most common prior art conducting polymer, polyacetylene, whichbecause of this, must be used in the same form as polymerized. In filmform it becomes highly porous fibrillar networks which are tough, cheap,and can be electrochemically doped very rapidly. Polyacetylene filmshave been used in light weight storage batteries and can also be used tomake Schottky barriers which exhibit a photovoltaic effect.

Successful environmentally stable doped conducting polymers aredescribed in two co-pending applications, the first, U.S. Pat. No.4,452,725 to S. T. Wellinghoff, S. A. Jenekhe (an inventor in thepresent application) and T. T. Kedrowski concerns conducting polymers ofN-alkyl 3,3'carbazolyl chemically doped with charge transfer acceptordopants such as the halogens. The second, Ser. No. 525,763 to S. A.Jenekhe (an inventor in the present invention) S. T. Wellinghoff and Y.A. Chen filed of even date herewith concerns complexes of poly (N-alkylphenothiazine) doped with charge transfer acceptors.

In the prior art electrochemical synthesis of electrically conductingpolymers the requisite monomers and dopants are dissolved in a solventand the resulting solutions are electrolyzed by application ofelectrical power. Doped electrically conducting polypyrrole,polythiophene, polyazulene, polypyrene, and others have beensuccessfully prepared by electrolysis of solutions of their monomerswith such dopant species as ClO₄ ⁻, BF₄ ⁻, PF₆ ⁻, etc. Simultaneouspolymerization and doping take place, thus producing the dopedconducting polymer in one step. However, compared to chemical synthesisfar fewer conducting polymers are available by electrochemicalsynthesis.

In the prior art chemical synthesis of electrically conducting polymerstwo distinct steps are usually required. First, the base polymer in theform of powder, pellet, or film is produced by polymerization of theappropriate monomer. Where the polymer film is desired and is notproduced directly during polymerization, the powder or pellet orwhatever prior form may also require processing into a film as anintermediate step. Second, the base polymer film, powder, or other formis chemically or electrochemically doped by exposing and contacting thevirgin polymer with suitable dopant in the vapor or liquid phase. Thisprior art two-step method of making electrically conducting polymers isexemplified in the preparation of doped p-type or n-type polyacetylenefilms as described by A. J. Heeger et al in U.S. Pat. Nos. 4,204,216 and4,222,903 (1980). Likewise the prior preparation of many other dopedconducting polymer complexes such as those based on poly p-phenylene,poly phenylene sulfide, metal-phthalocyanines, polyquinolines, etc.,follows the two-step chemical synthesis procedure.

In the prior art two-step method of synthesizing doped conductingpolymers uniformity of doping in the base solid polymer has beendifficult to achieve. Nonuniformity of doping and inherently low ratesof doping are so partly because of their dependence on the diffusivityof the doping species, the physical form, density, surface area,molecular structure, and crystallinity of the starting base polymer. Thechemical doping step may also produce undesired chemical transformationsin the starting backbone polymer structure, such as crosslinking, to theextent of precluding further processibility of the doped conductingpolymer.

One attempt by L. W. Shacklette et al (J.Chem.Phys. 73, 4098 (1980)) toachieve a one-step method of chemical synthesis of doped conductingpolymers consisted in the solid-state polymerization and doping ofpara-phenylene oligomers which have a degree of polymerization from 2 to6, i.e., biphenyl, para-terphenyl, para-quarterphenyl, etc., by arsenicpentafluoride AsF₅ vapor. However, the monomer, para-phenylene, does notpolymerize with AsF₅. Thus, this is still more or less a two-step methodin which first the oligomers are produced from the monomer and secondlythe oligomers are further polymerized and simultaneously doped with AsF₅to yield a doped conducting poly p-phenylene.

SUMMARY OF THE INVENTION

The present invention provides a one-step method for the chemicalsynthesis of iodine-doped electrically conducting polymers in the classof poly N-alkylcarbazoles and which exhibit electrical conductivity inthe range characteristic of semiconductors. The method consists incombining two previously separate chemical synthesis steps, thepolymerization of monomers to high molecular weight materials and thechemical doping with a charge-transfer acceptor dopant, into one toyield doped conducting polymer products. The method has been used toprepare a series of iodine-doped poly N-alkylcarbazoles semiconductors.

In accordance with the present invention it has been found that certainmonomers can be simultaneously polymerized and doped by iodine.Synthesis of iodine-doped polymer complexes from N-alkylcarbazole andN-alkydihalocarbazole monomers with the general formulas: ##STR1## whereR is H, CH₃, or C₂ H₅, X and H and both X's are Br or I or Y is H andboth X's are Br or I can be achieved by simultaneous polymerization anddoping in liquid iodine. H or Br or I, can be achieved by simultaneouspolymerization and doping in liquid iodine.

In accordance with the present invention new highly conducting,environmentally stable, iodine-dope polymers with the structures,##STR2## where R is H and where n is an integer, have been successfullyprepared by the one-step method of chemical synthesis. Also,iodine-doped poly(N-methyl 3,3'-carbazolyl), a polymer with the abovestructure (II), has been similarly prepared. Other iodine-dopedconducting polymers of as yet unknown molecular structures have beensimilarly prepared.

In accordance with the present invention when carbazole monomersrepresented by (I) are mixed singly, or in pairs, with iodine in avessel and heated to melt the solid mixtures to form a homogeneoussolution, the monomers spontaneously polymerize in air or inert orevacuated atmosphere to form a high molecular weight solid materialwhich is simultaneously doped by iodine. No other solvent or catalyst orinitiator is essential to the synthesis. The ability to effectpolymerization of carbazole and its derivatives and simultaneously dopein liquid iodine is probably due to many factors acting favorablytogether, including: the monomers (I) are good electron donors; iodineis a good electron acceptor that may form charge transfer complexes withthe polymers and/or monomers; iodine is a good solvent for the monomers;liquid iodine is a highly polarizable solvent which ionizes mostly as2I₂ =I⁺ +I₃ ⁻.

The as-synthesized conducting polymers are uniformly doped amorphousmaterials with conductivity in the range 10⁻⁴ to 1/ohm-cm depending onthe initial monomer and the degree of polymerization and dopingachieved. The kinetics of polymerization and doping in turn depend onthe reaction temperature and atmosphere. At a suitable temperature atwhich polymerization and doping is carried out in liquid iodine, thedegree of polymerization and doping achieved depend on the duration ofthe reaction. Furthermore, the electrical, mechanical and otherproperties of the as-synthesized doped polymers are convenientlyregulated by varying the polymerization and doping reaction conditionsof temperature, time, atmosphere, and concentration of reactants. Themethod of the present invention thus enables the preparation ofiodine-doped electrically conducting polymers from suitable monomers inone step.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In carrying out the one-step method of preparing electrically conductingpolymers in accordance with the present invention, the starting monomersare mixed with iodine to form a liquid solution in the temperature range80°-200° C. in a vessel open to air or sealed from air in inert gas orevacuated atmosphere. Simultaneous polymerization and doping is effectedby holding the solution at a temperature in that range and forsufficient time while stirring. The concentration of the initialsolution as measured by the starting molar ratios of all monomers toiodine should preferably be no more than 1.00.

In carrying out the method of the present invention for producingiodine-doped polycarbazoles the starting monomers are listed in Table 1.Homopolymers may be produced by using a single starting monomer or apair of them. Co-polymers may be produced by employing two monomersdiffering in the N-alkyl group or polymerization sites, for example, thepairs of monomers A and D or B and E.

                  TABLE 1                                                         ______________________________________                                        CARBAZOLE MONOMERS                                                            Groups         Monomer                                                        ______________________________________                                        R = H, x = y = H                                                                             Carbazole (CZ)     A                                           R = H, x = Br, y = H                                                                         3,3'-Dibromcarbazole (DBCZ)                                                                      B                                           R = CH, x = y = H                                                                            N═Methyl Carbazole (NMCZ)                                                                    C                                           R = CH, x = Br, y = H                                                                        N--methyl 3,3'-Dibromo-                                                                          D                                                          carbazole (NMDBCZ)                                             R = H, x = H, y = Br                                                                         2,2'-Dibromocarbazole                                                                            E                                                          (2,2' DBCZ)                                                    R = CH, x = H, y = Br                                                                        N--methyl 2,2'-Dibromo-                                                                          F                                                          carbazole (2,2' NMDBCZ)                                        ______________________________________                                    

One preferred procedure is to partially fill a vessel with the powderedmonomer or monomers. Solid iodine is added and mixed with themonomer(s). The vessel is then heated to the desired temperature in therange 80°-200° C. As the mixture completely melts to form a homogeneoussolution stirring is initiated by a mechanical stirrer, magneticstirrer, or manually with a stirring rod. The viscosity of the solutionat this point is either close to or a few times to at most about anorder of magnitude greater than that of the pure liquid iodine which isabout 0.5727 mm² /s at 116° C., depending on the initial concentration.Onset of rapid polymerization and doping is evidenced by the increasingviscosity and a gaseous product evolved. The kinetics of polymerizationand doping may thus be followed conveniently by the amount of gasevolution or by the rapidly increasing viscosity of the polymerizingsolution which may increase by several orders of magnitude within ashort time (minutes). After the desired level of polymerization anddoping is achieved the heat source is removed and polymerization may bestopped by quenching with distilled water, inert organic solvents suchas methanol or ethanol, or aqueous solutions such as sodium thiosulfatesolutions.

The as-synthesized doped conducting polymers are repeatedly washed withsuitable inert solvents or solutions to extract any excess iodine.Alcohols and sodium thiosulfate solutions extracts excess iodine fromsolid samples readily. The polymer complexes can also be rid of excessiodine by warming gradually to 40°-70° C. and allowing iodine to diffuseout of the samples. Samples washed with liquids are conveniently driedto rid them of the liquids and any residual iodine by drying in a vacuumoven at low temperatures (less than 50° C.)

Films, fibers, or other shapes may be produced directly from the dopedmolten polymer. Films are produced by casting onto substrates such asglass, alumina, or metallic aluminum. Fibers are drawn directly from themelt as soon as the viscosity is high enough or by removing the sourceof heat and cooling to high viscosity liquids. Other shapes areconveniently obtained by molding techniques using the as-synthesizeddoped molten polymer. Depending on the extent of polymerizationiodine-doped polymer complexes are also completely or partially sobublein solvents such as acetone, DMF, THF, and nitrobenzene or meltprocessible to films, fibers, or other shapes.

Another procedure is to mix the requisite monomer or monomers and iodinecrystals thoroughly by grinding them together and placing the mixture ina vessel. The vessel is then immersed in a constant temperature bath.The reactant may be exposed to air, to flowing inert gas, or the vesselmay be evacuated and sealed. In the first two cases stirring may be bymechanical or manual means, while in the latter it must be by mechanicalmeans. The polymerization is carried out at constant temperature. Whenthe desired degree of polymerization is reached the reaction is quenchedas described above.

In another procedure the mixture of iodine and the chosen monomer ormonomers is placed in a shallow vessel of large surface area comparedwith the volume of the reactants. The mixture is spread uniformly overthe base of the vessel. The vessel is then heated to the desiredtemperature or placed in an environment, such as an oven, already at thedesired temperature. The reaction is allowed to proceed until thedesired level of polymerization is achieved. A doped conducting polymerfilm may be produced directly by this procedure.

The preferred initial concentration of the monomer or monomers in themixture described above is in the range of 1 to 60% by weight.Concentrations on either side of this range may also be used, however.Highly concentrated reactant mixtures, in which the molar ratio of themonomer or monomers to iodine exceeds 1.0, usually result in poor yieldsof the desired polymer and in incomplete doping. Furthermore thereaction kinetics are faster with lower concentrations of the monomer ormonomers.

Although, as stated above, doped conducting polymers may be produced ina one step process in air, flowing inert gas, or in a sealed evacuatedchamber, the former two are preferable. The reaction kinetics are fasterin those atmospheres than in a sealed low pressure environment. Somemonomers, particularly carbazole and dihalo-carbazole, polymerize atmuch slower rates in evacuated vessels.

The invention is further illustrated by the following examples whereinthe monomers listed in Table 1 are simultaneously polymerized and dopedto yield iodine-doped conducting polymers which exhibit electricalconductivity in the range characteristic of semiconductors. Theinvention is not limited to these examples.

EXAMPLE 1

Carbazole (CZ) (50 g) was suspended in carbon disulfide (CS₂) (473 ml)and heated till reflux. To this warm suspension being stirredmagnetically was added (dropwise) a solution of 34 ml (0.658 mole) Br₂in 130 ml CS₂. HBr gas was given off very rapidly. Slow addition ofbromine solution was used to control the rate of gas evolution. Uoncompletion of Br₂ solution addition heating of the reaction solution wasstopped and the stirring continued for several hours. The precipitateformed was collected on a glass filter and washed several times with CS₂to yield white crystals of 3,6 dibromocarbazole (DBCZ). The yield was 67g (0.206 mole) or 70% of the theoretical. The yield can be improved bycooling the reaction solution prior to filtration and by washing withcold CS₂. However, this may increase the chances of co-precipitation ofmonobromo-carbazole if present in the reaction solution. The meltingpoint was 211.5° C. compared to 211°-213° C. literature value.

Sixty grams (60 g) of CZ was placed in a 1000 ml reaction flask to which90 ml dimethyl sulfate and 300 ml Acetone (gold label) was added. Themechanical stirrer was turned on to 200 rpm. After 5 minutes of stirring60 g NaOH pellets was added to the reaction mixture, followed bydropwise addition of 100 ml of distilled water until completion and asalt layer could be seen. The stirring rate was increased from 200 rpmto 400 rpm for 3 minutes and then back to 200 rpm. The reaction vesseltemperature was increased from 25° C. to 56° C. and refluxed for 1 hrand then cooled 40 minutes. The reaction mixture was poured into 3liters of cold distilled water precipitating white crystals ofN-methylcarbazole (NMCZ). The product was collected, dissolved inacetone and recrystallized in one liter of distilled water. The NMCZproduct was dried in a vacuum oven at 80 C. overnight. The yield was61.9 g or 95.2%; the melting point was 87.4° C. compared with literaturevalue of 88° C.

Thirty grams (30 g) of DBCZ was dissolved in 150 ml acetone/30 mldimethyl sulfate (CH₃)₂ SO₄. Next, 30 g NaOH pellets was added to thereaction solution. Distilled water was dripped slowly into the reactionflask with stirring until a salt layer could be seen. The flask wasshaken vigorously for several minutes and then the solution was broughtto reflux by heating for 15 minutes after which is was allowed to cool.After 0.5 hr of cooling the reaction solution was poured into coldwater, rapidly precipitating white crystals of3,6-dibromo-N-methyl-carbazole (NMDBCZ). The precipitate wasrecrystallized from ethanol to give quantitative yields. The meltingpoint was 159° C. compared to 158°-160° C. previously reported.

Five grams (5 g) (0.03 mole) CZ and 9.75 g (0.03 mole) DBCZ were placedin 250 ml beaker. To this was added 18 g (0.07 mole) sublimed iodinecrystals. The solids were thoroughly mixed with a glass stirring rod.The beaker was placed on a hot plate and heated to 130° C. whilestirring. A violet-blush to black colored solution of low viscosity wasobtained. With continuous stirring, a fuming gas evolution was observedwith a few seconds of complete dissolution of solids. Within the nextfew minutes the solution viscosity begin increasing continuously. After10 minutes long black fibers could be drawn from the high viscosity meltof doped polymer. At about 15 minutes of dissolution some of the dopedpolymer melt was withdrawn and poured into a beaker of distilled water.Films were cast from the remaining solid product by withdrawing portionsonto 2 inch square ceramic alumina substrates maintained at about 50° C.on a hot plate. The remaining product in the reaction vessel was cooledin air. The three fractions were repeatedly washed with methanol oraqueous Na₂ S₂ O₃ and subsequently dried in a vacuum oven at 45° C.

Electrical conductivity measurements on the three fractions usingstandard 4-point probe, 2-point contact, and in the case of films alsoby a contactless technique indicated conductivity close to 0.1 to1/ohm-cm. The polymer backbone structure was judged to bepoly(3,3'-carbazolyl) from the close resemblance of the infraredspectrum with that of the pure carbazole monomer and considerations ofboth the mechanism of polymerization reaction and the gaseous product.Gas absorption infrared spectroscopy showed HBr to be a major componentof the gas. Though HI was not observed in the infrared spectra itspresence cannot be ruled out because of the extremely high resolutionusually required to detect the gas even at long path lengths and highpressure.

EXAMPLE 2

The procedure was similar to Example 1 except that 1 g (0.0055 mole)NMCZ, 1.883 g (0.0055 mole) NMDBCZ, and 4.20 g (0.0166 mole) I₂ wasused. The molar ratio of monomers to iodine was 0.667 or 40.7% wtmonomer's solution in liquid iodine at dissolution.

The polymer backbone structure was determined to be poly(N-methyl3,3'-carbazolyl) The room temperature dc conductivity was between 0.15and 2.5/ohm-cm.

EXAMPLE 3

The procedure was similar to Example 1 except that 1 g NMCZ, 1.79 gDBCZ, and 4.20 g I₂ was used. The molar ratio of monomers to iodine was0.667 or 39.9% wt monomer's solution in liquid iodine at dissolution.The polymer backbone structure was determined to be the co-polymerpoly(3,3'-carbazolyl-co-N-methyl 3,3'-carbazolyl). The dc conductivityat room temperature was about 10⁻³ /ohm-cm.

EXAMPLE 4

Ten (10) mixtures of iodine and the chosen monomer or monomers wereprepared using single monomers or pairs of monomers as shown in TABLE 2.In those cases where pairs of monomers were used, equimolar mixtureswere employed. In each case, whether a single monomer or a pair ofmonomers was used, the monomer or monomers formed fifteen percent, byweight, of the mixture with iodine. Polymerization of the mixtures wasperformed either in a beaker or a watch glass by heating the vessel on ahot plate to a temperature in the range of 120° to 125° C. The vesselwas held at that temperature for 10 to 15 minutes and then removed fromthe hot plate. Films or pressed pellets were made from the dopedconducting polymers thus produced. D.C. conductivity measurements atroom temperature performed on these samples revealed conductivities inthe range 10⁻⁴ to 2.5/ohm-cm as shown in TABLE 2.

                  TABLE 2                                                         ______________________________________                                        Polymerization and Doping in Liquid Iodine                                              Gas       Polymer       σ(25° C.)                      Monomers(s)                                                                             Evolved   Structure     (ohm.sup.-1 cm.sup.-1)                      ______________________________________                                        CZ        other     unknown       ˜10.sup.-4                            DBCZ      HBr, other                                                                              poly(3,3'-carba-                                                                            1-2.5                                                           zolyl) (PCZ)                                              NMCZ      other     unknown       ˜10.sup.-4                            NMDBCZ    HBr, other                                                                              polyl(N--methyl 3,                                                                          0.15-2.5                                                        3'-carbazolyl)                                                                (PNMCZ)                                                   CZ, DBCZ  HBr, other                                                                              PCZ           0.1-1.0                                     CZ, NMCZ  other     unknown       ˜10.sup.-4 -10.sup.-3                 CZ, NMDBCZ                                                                              HBr, other                                                                              poly(3,3'-carba-                                                                            5 × 10.sup.-3                                             zolyl-N--methyl-                                                              carbazolyl)                                               DBCZ, NMCZ                                                                              HBr, other                                                                              poly(3,3'-carba-                                                                            ˜10.sup.-3                                                zolyl-N--methyl                                                               carbazolyl                                                DBCZ,     HBr, other                                                                              poly(3,3'-carba-                                                                            ˜10.sup.-3                            NMDBCZ              zolyl-N--methyl                                                               carbazolyl)                                               NMCZ,     HBr, other                                                                              PNMCZ         ˜1                                    NMDBCZ                                                                        ______________________________________                                    

The gas evolved during polymerization of the mixtures of iodine and themonomer or monomers and the solid polymer complexes were studied byFourier Transform Infrared (FTIR) spectroscopy in order to gainknowledge of the mechanism of polymerization and structure of thepolymers. A special FTIR gas absorption cell was constructed of pyrexglass. Two KCL windows were attached to provide a path length of 12.70cm. New 30 to 50% wt mixtures of monomers with iodine were prepared andplaced in the cells which were subsequently evacuated and sealed. FTIRspectra in the range 400 to 4000/cm were taken before heating thesamples, after heating to 120° to 25° C. for 5 minutes, and afteropening the cells. Also films were cast on KCL windows from the solidreaction products and their FTIR spectra taken. HBr gas with bands inthe range 2400 to 2800/cm was clearly identified in polymerizingmixtures containing dibromo-monomers. The spectra of one or two othergases were revealed but have as yet not been positively identified.However, HI which was suspected to be present was not revealed by FTIR,perhaps because the sensitivity, path length, and concentration were nothigh enough for detection.

Thermal analysis of mixtures of iodine and the monomer or monomers andiodine-doped polycarbazoles synthesized by simultaneous polymerizationand doping was carried out by differential scanning calorimetry (DSC)and thermogravimetric analysis (TGA) using a DuPont 990 Thermal Analyzerequipped with a 951 TGA and a 910 DSC units. Measurements were made in anitrogen atmosphere at a heating rate of 10° C./min and from 25° to 300°C. or 600° on the DSC and from 25° to 50° C. on the TGA. The DSC datarevealed a Tg in the range of 90°-164° C. and a melting temperature inthe range 156°-200° C. for the various samples of iodine-dopedpolycarbazoles. Muliple exothermic peaks occurring at temperatures inthe range 52°-114° C. were also observed and interpreted as due to bothloss of some iodine species and further polymerization reactions. TheTGA data revealed onset of weight loss in the temperature range 52°-95°C. followed by 48-64% weight loss up to about 300° C. Thereafterconstant weight was maintained up to 500°-600° C. after which thermaldecomposition of the polymer complexes followed. The TGA results areconsistent with the DSC data suggesting further polymerization and lossof volatiles on heating.

The embodiments of the invention in which an exclusive property or rightis claimed are defined as follows:
 1. A one-step process for makingsolid electrically conducting organic polymers comprising the stepsof:combining an amount of a monomer selected from a group consisting ofN-alkyl carbazole and N-alkyldihalocarbazole monomers or combinationthereof of the general formula ##STR3## where R is H or CH₃, X is H andboth Y's are Br or I, or Y is H and both X's are Br or I, with an amountof I₂ wherein said I₂ functions as a charge transfer acceptor dopant andheating said combination to form a liquid melt solution thereof; whereinthe concentration of said monomers in said melt solution is in the rangeof 1% to 60% by weight and wherein the concentration of said I₂ is fromabout 99% to 40% by weight; polymerizing and chemically doping themonomer in said melt solution at a temperature between 80° C. and 200°for a time sufficient to produce the degree of polymerization desired atthe temperature selected using an atmosphere selected from inert gas,air, or a partial vacuum.
 2. The process of claim 1 wherein said N-alkylcarbazole is one selected from the group consisting of carbazole andN-methyl carbazole and wherein said N-alkyldihalocarbazole is onewherein R is H or CH₃, Y is H and X is Br.
 3. The process of claim 1wherein said n-alkyl carbazole is one selected from the group consistingof carbazole and N-methyl carbazole and wherein saidN-alkyldihalocarbazole is one wherein R is H or CH₃, Y is H and X is I₂.4. The process of claim 1 wherein said electrically conducting polymeris a copolymer.
 5. The process of claim 2 wherein said electricallyconducting polymer is a copolymer.
 6. The process of claim 3 whereinsaid electrically conducting polymer is a copolymer.
 7. The process ofclaim 1 wherein said electrically conducting polymer is a homopolymer.8. The process of claim 2 wherein said electrically conducting polymeris a homopolymer.
 9. The process of claim 3 wherein said electricallyconducting polymer is a homopolymer.
 10. The process of claim 1 whereinsaid heating takes place in an air atmosphere.
 11. The process of claim1 wherein said heating takes place in an atmosphere of inert gas. 12.The process of claim 1 wherein said mixture is heated and polymerized ona substrate such that a film of said polymer is formed on the substrate.13. The process of claim 1 further comprising the step of drawing fibersof the electrically conducting polymer directly from said melt.